I've been concerned with the effect of the B/L ratio per your nomenclature:
not the B/A ratio (which does change as B/L changes, but it's determined by B/L and the intended stroke length)
Every one of my graphed examples covering B/L ratios from 1.333 to 5.0 shares the same precisely 150 mm stroke (therefore same volume).
If I'm analysing a ratio that doesn't give the correct stroke then I simply scale the overall lengths so that it does.
I also keep the same point of effort, which is set at 400 mm, and same arc of 135 degrees - covering points #1 & #3.